Although the individual steps of acylation and hydroxylation of phosphatides are known (see U.S. Pat. Nos. 3,301,881 and 2,629,662, respectively), neither provides a product having desirable water dispersability characteristics. It was therefore surprising to discover that employing both steps in combination would result in a phosphatide having significantly improved water dispersability.
More particularly, it was surprising to discover that phosphatides (commonly referred to as "lecithins") can have substantially enhanced water dispersability characteristics when made more lipophilic by the addition of acyl groups according to the procedure of U.S. Pat. No. 3,301,881 and more hydrophilic by the addition of hydroxyl groups according to the process of U.S. Pat. No. 2,629,662.
In a preferred embodiment of the invention, we acylate the amino groups of a phosphatidic material utilizing a carboxylic acid anhydride containing not more than ten carbon atoms exclusive of any aryl groups and while the mixture is still at an acidic pH, hydroxylating the phosphatidic material with hydrogen peroxide, and thereafter substantially neutralizing the mixture.